_ Git - rust-lightning/blob - src/ln/router.rs

   1 use secp256k1::key::PublicKey;
   2 use secp256k1::{Secp256k1,Message};
   3 use secp256k1;
   4
   5 use bitcoin::util::hash::Sha256dHash;
   6
   7 use chain::chaininterface::ChainWatchInterface;
   8 use ln::channelmanager;
   9 use ln::msgs::{ErrorAction,HandleError,RoutingMessageHandler,MsgEncodable,NetAddress,GlobalFeatures};
  10 use ln::msgs;
  11 use util::logger::Logger;
  12
  13 use std::cmp;
  14 use std::sync::{RwLock,Arc};
  15 use std::collections::{HashMap,BinaryHeap};
  16 use std::collections::hash_map::Entry;
  17 use std;
  18
  19 /// A hop in a route
  20 #[derive(Clone)]
  21 pub struct RouteHop {
  22         pub pubkey: PublicKey,
  23         /// The channel that should be used from the previous hop to reach this node.
  24         pub short_channel_id: u64,
  25         /// The fee taken on this hop. For the last hop, this should be the full value of the payment.
  26         pub fee_msat: u64,
  27         /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
  28         /// expected at the destination, in excess of the current block height.
  29         pub cltv_expiry_delta: u32,
  30 }
  31
  32 /// A route from us through the network to a destination
  33 #[derive(Clone)]
  34 pub struct Route {
  35         /// The list of hops, NOT INCLUDING our own, where the last hop is the destination. Thus, this
  36         /// must always be at least length one. By protocol rules, this may not currently exceed 20 in
  37         /// length.
  38         pub hops: Vec<RouteHop>,
  39 }
  40
  41 struct DirectionalChannelInfo {
  42         src_node_id: PublicKey,
  43         last_update: u32,
  44         enabled: bool,
  45         cltv_expiry_delta: u16,
  46         htlc_minimum_msat: u64,
  47         fee_base_msat: u32,
  48         fee_proportional_millionths: u32,
  49 }
  50
  51 impl std::fmt::Display for DirectionalChannelInfo {
  52         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  53                 write!(f, "src_node_id {}, last_update {}, enabled {}, cltv_expiry_delta {}, htlc_minimum_msat {}, fee_base_msat {}, fee_proportional_millionths {}", log_pubkey!(self.src_node_id), self.last_update, self.enabled, self.cltv_expiry_delta, self.htlc_minimum_msat, self.fee_base_msat, self.fee_proportional_millionths)?;
  54                 Ok(())
  55         }
  56 }
  57
  58 struct ChannelInfo {
  59         features: GlobalFeatures,
  60         one_to_two: DirectionalChannelInfo,
  61         two_to_one: DirectionalChannelInfo,
  62 }
  63
  64 impl std::fmt::Display for ChannelInfo {
  65         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  66                 write!(f, "features: {}, one_to_two: {}, two_to_one: {}", log_bytes!(self.features.encode()), self.one_to_two, self.two_to_one)?;
  67                 Ok(())
  68         }
  69 }
  70
  71 struct NodeInfo {
  72         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
  73         channels: Vec<(u64, Sha256dHash)>,
  74         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
  75         channels: Vec<u64>,
  76
  77         lowest_inbound_channel_fee_base_msat: u32,
  78         lowest_inbound_channel_fee_proportional_millionths: u32,
  79
  80         features: GlobalFeatures,
  81         last_update: u32,
  82         rgb: [u8; 3],
  83         alias: [u8; 32],
  84         addresses: Vec<NetAddress>,
  85 }
  86
  87 impl std::fmt::Display for NodeInfo {
  88         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
  89                 write!(f, "features: {}, last_update: {}, lowest_inbound_channel_fee_base_msat: {}, lowest_inbound_channel_fee_proportional_millionths: {}, channels: {:?}", log_bytes!(self.features.encode()), self.last_update, self.lowest_inbound_channel_fee_base_msat, self.lowest_inbound_channel_fee_proportional_millionths, &self.channels[..])?;
  90                 Ok(())
  91         }
  92 }
  93
  94 struct NetworkMap {
  95         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
  96         channels: HashMap<(u64, Sha256dHash), ChannelInfo>,
  97         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
  98         channels: HashMap<u64, ChannelInfo>,
  99
 100         our_node_id: PublicKey,
 101         nodes: HashMap<PublicKey, NodeInfo>,
 102 }
 103
 104 impl std::fmt::Display for NetworkMap {
 105         fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
 106                 write!(f, "Node id {} network map\n[Channels]\n", log_pubkey!(self.our_node_id))?;
 107                 for (key, val) in self.channels.iter() {
 108                         write!(f, " {}: {}\n", key, val)?;
 109                 }
 110                 write!(f, "[Nodes]\n")?;
 111                 for (key, val) in self.nodes.iter() {
 112                         write!(f, " {}: {}\n", log_pubkey!(key), val)?;
 113                 }
 114                 Ok(())
 115         }
 116 }
 117
 118 impl NetworkMap {
 119         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 120         #[inline]
 121         fn get_key(short_channel_id: u64, chain_hash: Sha256dHash) -> (u64, Sha256dHash) {
 122                 (short_channel_id, chain_hash)
 123         }
 124
 125         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 126         #[inline]
 127         fn get_key(short_channel_id: u64, _: Sha256dHash) -> u64 {
 128                 short_channel_id
 129         }
 130
 131         #[cfg(feature = "non_bitcoin_chain_hash_routing")]
 132         #[inline]
 133         fn get_short_id(id: &(u64, Sha256dHash)) -> &u64 {
 134                 &id.0
 135         }
 136
 137         #[cfg(not(feature = "non_bitcoin_chain_hash_routing"))]
 138         #[inline]
 139         fn get_short_id(id: &u64) -> &u64 {
 140                 id
 141         }
 142 }
 143
 144 /// A channel descriptor which provides a last-hop route to get_route
 145 pub struct RouteHint {
 146         pub src_node_id: PublicKey,
 147         pub short_channel_id: u64,
 148         pub fee_base_msat: u32,
 149         pub fee_proportional_millionths: u32,
 150         pub cltv_expiry_delta: u16,
 151         pub htlc_minimum_msat: u64,
 152 }
 153
 154 /// Tracks a view of the network, receiving updates from peers and generating Routes to
 155 /// payment destinations.
 156 pub struct Router {
 157         secp_ctx: Secp256k1<secp256k1::VerifyOnly>,
 158         network_map: RwLock<NetworkMap>,
 159         chain_monitor: Arc<ChainWatchInterface>,
 160         logger: Arc<Logger>,
 161 }
 162
 163 macro_rules! secp_verify_sig {
 164         ( $secp_ctx: expr, $msg: expr, $sig: expr, $pubkey: expr ) => {
 165                 match $secp_ctx.verify($msg, $sig, $pubkey) {
 166                         Ok(_) => {},
 167                         Err(_) => return Err(HandleError{err: "Invalid signature from remote node", action: None}),
 168                 }
 169         };
 170 }
 171
 172 impl RoutingMessageHandler for Router {
 173         fn handle_node_announcement(&self, msg: &msgs::NodeAnnouncement) -> Result<bool, HandleError> {
 174                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 175                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &msg.contents.node_id);
 176
 177                 if msg.contents.features.requires_unknown_bits() {
 178                         panic!("Unknown-required-features NodeAnnouncements should never deserialize!");
 179                 }
 180
 181                 let mut network = self.network_map.write().unwrap();
 182                 match network.nodes.get_mut(&msg.contents.node_id) {
 183                         None => Err(HandleError{err: "No existing channels for node_announcement", action: Some(ErrorAction::IgnoreError)}),
 184                         Some(node) => {
 185                                 if node.last_update >= msg.contents.timestamp {
 186                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 187                                 }
 188
 189                                 node.features = msg.contents.features.clone();
 190                                 node.last_update = msg.contents.timestamp;
 191                                 node.rgb = msg.contents.rgb;
 192                                 node.alias = msg.contents.alias;
 193                                 node.addresses = msg.contents.addresses.clone();
 194                                 Ok(msg.contents.excess_data.is_empty() && msg.contents.excess_address_data.is_empty() && !msg.contents.features.supports_unknown_bits())
 195                         }
 196                 }
 197         }
 198
 199         fn handle_channel_announcement(&self, msg: &msgs::ChannelAnnouncement) -> Result<bool, HandleError> {
 200                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 201                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_1, &msg.contents.node_id_1);
 202                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.node_signature_2, &msg.contents.node_id_2);
 203                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_1, &msg.contents.bitcoin_key_1);
 204                 secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.bitcoin_signature_2, &msg.contents.bitcoin_key_2);
 205
 206                 //TODO: Call blockchain thing to ask if the short_channel_id is valid
 207                 //TODO: Only allow bitcoin chain_hash
 208
 209                 if msg.contents.features.requires_unknown_bits() {
 210                         panic!("Unknown-required-features ChannelAnnouncements should never deserialize!");
 211                 }
 212
 213                 let mut network = self.network_map.write().unwrap();
 214
 215                 match network.channels.entry(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 216                         Entry::Occupied(_) => {
 217                                 //TODO: because asking the blockchain if short_channel_id is valid is only optional
 218                                 //in the blockchain API, we need to handle it smartly here, though its unclear
 219                                 //exactly how...
 220                                 return Err(HandleError{err: "Already have knowledge of channel", action: Some(ErrorAction::IgnoreError)})
 221                         },
 222                         Entry::Vacant(entry) => {
 223                                 entry.insert(ChannelInfo {
 224                                         features: msg.contents.features.clone(),
 225                                         one_to_two: DirectionalChannelInfo {
 226                                                 src_node_id: msg.contents.node_id_1.clone(),
 227                                                 last_update: 0,
 228                                                 enabled: false,
 229                                                 cltv_expiry_delta: u16::max_value(),
 230                                                 htlc_minimum_msat: u64::max_value(),
 231                                                 fee_base_msat: u32::max_value(),
 232                                                 fee_proportional_millionths: u32::max_value(),
 233                                         },
 234                                         two_to_one: DirectionalChannelInfo {
 235                                                 src_node_id: msg.contents.node_id_2.clone(),
 236                                                 last_update: 0,
 237                                                 enabled: false,
 238                                                 cltv_expiry_delta: u16::max_value(),
 239                                                 htlc_minimum_msat: u64::max_value(),
 240                                                 fee_base_msat: u32::max_value(),
 241                                                 fee_proportional_millionths: u32::max_value(),
 242                                         }
 243                                 });
 244                         }
 245                 };
 246
 247                 macro_rules! add_channel_to_node {
 248                         ( $node_id: expr ) => {
 249                                 match network.nodes.entry($node_id) {
 250                                         Entry::Occupied(node_entry) => {
 251                                                 node_entry.into_mut().channels.push(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash));
 252                                         },
 253                                         Entry::Vacant(node_entry) => {
 254                                                 node_entry.insert(NodeInfo {
 255                                                         channels: vec!(NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)),
 256                                                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 257                                                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 258                                                         features: GlobalFeatures::new(),
 259                                                         last_update: 0,
 260                                                         rgb: [0; 3],
 261                                                         alias: [0; 32],
 262                                                         addresses: Vec::new(),
 263                                                 });
 264                                         }
 265                                 }
 266                         };
 267                 }
 268
 269                 add_channel_to_node!(msg.contents.node_id_1);
 270                 add_channel_to_node!(msg.contents.node_id_2);
 271
 272                 Ok(msg.contents.excess_data.is_empty() && !msg.contents.features.supports_unknown_bits())
 273         }
 274
 275         fn handle_htlc_fail_channel_update(&self, update: &msgs::HTLCFailChannelUpdate) {
 276                 match update {
 277                         &msgs::HTLCFailChannelUpdate::ChannelUpdateMessage { ref msg } => {
 278                                 let _ = self.handle_channel_update(msg);
 279                         },
 280                         &msgs::HTLCFailChannelUpdate::ChannelClosed { ref short_channel_id } => {
 281                                 let mut network = self.network_map.write().unwrap();
 282                                 if let Some(chan) = network.channels.remove(short_channel_id) {
 283                                         network.nodes.get_mut(&chan.one_to_two.src_node_id).unwrap().channels.retain(|chan_id| {
 284                                                 chan_id != NetworkMap::get_short_id(chan_id)
 285                                         });
 286                                         network.nodes.get_mut(&chan.two_to_one.src_node_id).unwrap().channels.retain(|chan_id| {
 287                                                 chan_id != NetworkMap::get_short_id(chan_id)
 288                                         });
 289                                 }
 290                         },
 291                 }
 292         }
 293
 294         fn handle_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<bool, HandleError> {
 295                 let mut network = self.network_map.write().unwrap();
 296                 let dest_node_id;
 297                 let chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
 298                 let chan_was_enabled;
 299
 300                 match network.channels.get_mut(&NetworkMap::get_key(msg.contents.short_channel_id, msg.contents.chain_hash)) {
 301                         None => return Err(HandleError{err: "Couldn't find channel for update", action: Some(ErrorAction::IgnoreError)}),
 302                         Some(channel) => {
 303                                 macro_rules! maybe_update_channel_info {
 304                                         ( $target: expr) => {
 305                                                 if $target.last_update >= msg.contents.timestamp {
 306                                                         return Err(HandleError{err: "Update older than last processed update", action: Some(ErrorAction::IgnoreError)});
 307                                                 }
 308                                                 chan_was_enabled = $target.enabled;
 309                                                 $target.last_update = msg.contents.timestamp;
 310                                                 $target.enabled = chan_enabled;
 311                                                 $target.cltv_expiry_delta = msg.contents.cltv_expiry_delta;
 312                                                 $target.htlc_minimum_msat = msg.contents.htlc_minimum_msat;
 313                                                 $target.fee_base_msat = msg.contents.fee_base_msat;
 314                                                 $target.fee_proportional_millionths = msg.contents.fee_proportional_millionths;
 315                                         }
 316                                 }
 317
 318                                 let msg_hash = Message::from_slice(&Sha256dHash::from_data(&msg.contents.encode()[..])[..]).unwrap();
 319                                 if msg.contents.flags & 1 == 1 {
 320                                         dest_node_id = channel.one_to_two.src_node_id.clone();
 321                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.two_to_one.src_node_id);
 322                                         maybe_update_channel_info!(channel.two_to_one);
 323                                 } else {
 324                                         dest_node_id = channel.two_to_one.src_node_id.clone();
 325                                         secp_verify_sig!(self.secp_ctx, &msg_hash, &msg.signature, &channel.one_to_two.src_node_id);
 326                                         maybe_update_channel_info!(channel.one_to_two);
 327                                 }
 328                         }
 329                 }
 330
 331                 if chan_enabled {
 332                         let node = network.nodes.get_mut(&dest_node_id).unwrap();
 333                         node.lowest_inbound_channel_fee_base_msat = cmp::min(node.lowest_inbound_channel_fee_base_msat, msg.contents.fee_base_msat);
 334                         node.lowest_inbound_channel_fee_proportional_millionths = cmp::min(node.lowest_inbound_channel_fee_proportional_millionths, msg.contents.fee_proportional_millionths);
 335                 } else if chan_was_enabled {
 336                         let mut lowest_inbound_channel_fee_base_msat = u32::max_value();
 337                         let mut lowest_inbound_channel_fee_proportional_millionths = u32::max_value();
 338
 339                         {
 340                                 let node = network.nodes.get(&dest_node_id).unwrap();
 341
 342                                 for chan_id in node.channels.iter() {
 343                                         let chan = network.channels.get(chan_id).unwrap();
 344                                         if chan.one_to_two.src_node_id == dest_node_id {
 345                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.two_to_one.fee_base_msat);
 346                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.two_to_one.fee_proportional_millionths);
 347                                         } else {
 348                                                 lowest_inbound_channel_fee_base_msat = cmp::min(lowest_inbound_channel_fee_base_msat, chan.one_to_two.fee_base_msat);
 349                                                 lowest_inbound_channel_fee_proportional_millionths = cmp::min(lowest_inbound_channel_fee_proportional_millionths, chan.one_to_two.fee_proportional_millionths);
 350                                         }
 351                                 }
 352                         }
 353
 354                         //TODO: satisfy the borrow-checker without a double-map-lookup :(
 355                         let mut_node = network.nodes.get_mut(&dest_node_id).unwrap();
 356                         mut_node.lowest_inbound_channel_fee_base_msat = lowest_inbound_channel_fee_base_msat;
 357                         mut_node.lowest_inbound_channel_fee_proportional_millionths = lowest_inbound_channel_fee_proportional_millionths;
 358                 }
 359
 360                 Ok(msg.contents.excess_data.is_empty())
 361         }
 362 }
 363
 364 #[derive(Eq, PartialEq)]
 365 struct RouteGraphNode {
 366         pubkey: PublicKey,
 367         lowest_fee_to_peer_through_node: u64,
 368         lowest_fee_to_node: u64,
 369 }
 370
 371 impl cmp::Ord for RouteGraphNode {
 372         fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
 373                 other.lowest_fee_to_peer_through_node.cmp(&self.lowest_fee_to_peer_through_node)
 374                         .then_with(|| other.pubkey.serialize().cmp(&self.pubkey.serialize()))
 375         }
 376 }
 377
 378 impl cmp::PartialOrd for RouteGraphNode {
 379         fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
 380                 Some(self.cmp(other))
 381         }
 382 }
 383
 384 struct DummyDirectionalChannelInfo {
 385         src_node_id: PublicKey,
 386         cltv_expiry_delta: u32,
 387         htlc_minimum_msat: u64,
 388         fee_base_msat: u32,
 389         fee_proportional_millionths: u32,
 390 }
 391
 392 impl Router {
 393         pub fn new(our_pubkey: PublicKey, chain_monitor: Arc<ChainWatchInterface>, logger: Arc<Logger>) -> Router {
 394                 let mut nodes = HashMap::new();
 395                 nodes.insert(our_pubkey.clone(), NodeInfo {
 396                         channels: Vec::new(),
 397                         lowest_inbound_channel_fee_base_msat: u32::max_value(),
 398                         lowest_inbound_channel_fee_proportional_millionths: u32::max_value(),
 399                         features: GlobalFeatures::new(),
 400                         last_update: 0,
 401                         rgb: [0; 3],
 402                         alias: [0; 32],
 403                         addresses: Vec::new(),
 404                 });
 405                 Router {
 406                         secp_ctx: Secp256k1::verification_only(),
 407                         network_map: RwLock::new(NetworkMap {
 408                                 channels: HashMap::new(),
 409                                 our_node_id: our_pubkey,
 410                                 nodes: nodes,
 411                         }),
 412                         chain_monitor,
 413                         logger,
 414                 }
 415         }
 416
 417         /// Dumps the entire network view of this Router to the logger provided in the constructor at
 418         /// level Trace
 419         pub fn trace_state(&self) {
 420                 log_trace!(self, "{}", self.network_map.read().unwrap());
 421         }
 422
 423         /// Get network addresses by node id
 424         pub fn get_addresses(&self, pubkey: &PublicKey) -> Option<Vec<NetAddress>> {
 425                 let network = self.network_map.read().unwrap();
 426                 network.nodes.get(pubkey).map(|n| n.addresses.clone())
 427         }
 428
 429         /// Marks a node as having failed a route. This will avoid re-using the node in routes for now,
 430         /// with an expotnential decay in node "badness". Note that there is deliberately no
 431         /// mark_channel_bad as a node may simply lie and suggest that an upstream channel from it is
 432         /// what failed the route and not the node itself. Instead, setting the blamed_upstream_node
 433         /// boolean will reduce the penalty, returning the node to usability faster. If the node is
 434         /// behaving correctly, it will disable the failing channel and we will use it again next time.
 435         pub fn mark_node_bad(&self, _node_id: &PublicKey, _blamed_upstream_node: bool) {
 436                 unimplemented!();
 437         }
 438
 439         /// Gets a route from us to the given target node.
 440         /// Extra routing hops between known nodes and the target will be used if they are included in
 441         /// last_hops.
 442         /// If some channels aren't announced, it may be useful to fill in a first_hops with the
 443         /// results from a local ChannelManager::list_usable_channels() call. If it is filled in, our
 444         /// (this Router's) view of our local channels will be ignored, and only those in first_hops
 445         /// will be used. Panics if first_hops contains channels without short_channel_ids
 446         /// (ChannelManager::list_usable_channels will never include such channels).
 447         /// The fees on channels from us to next-hops are ignored (as they are assumed to all be
 448         /// equal), however the enabled/disabled bit on such channels as well as the htlc_minimum_msat
 449         /// *is* checked as they may change based on the receiving node.
 450         pub fn get_route(&self, target: &PublicKey, first_hops: Option<&[channelmanager::ChannelDetails]>, last_hops: &[RouteHint], final_value_msat: u64, final_cltv: u32) -> Result<Route, HandleError> {
 451                 // TODO: Obviously *only* using total fee cost sucks. We should consider weighting by
 452                 // uptime/success in using a node in the past.
 453                 let network = self.network_map.read().unwrap();
 454
 455                 if *target == network.our_node_id {
 456                         return Err(HandleError{err: "Cannot generate a route to ourselves", action: None});
 457                 }
 458
 459                 if final_value_msat > 21_000_000 * 1_0000_0000 * 1000 {
 460                         return Err(HandleError{err: "Cannot generate a route of more value than all existing satoshis", action: None});
 461                 }
 462
 463                 // We do a dest-to-source Dijkstra's sorting by each node's distance from the destination
 464                 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty A*").
 465                 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
 466                 // to use as the A* heuristic beyond just the cost to get one node further than the current
 467                 // one.
 468
 469                 let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
 470                         src_node_id: network.our_node_id.clone(),
 471                         cltv_expiry_delta: 0,
 472                         htlc_minimum_msat: 0,
 473                         fee_base_msat: 0,
 474                         fee_proportional_millionths: 0,
 475                 };
 476
 477                 let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
 478                 let mut dist = HashMap::with_capacity(network.nodes.len());
 479
 480                 let mut first_hop_targets = HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
 481                 if let Some(hops) = first_hops {
 482                         for chan in hops {
 483                                 let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
 484                                 if chan.remote_network_id == *target {
 485                                         return Ok(Route {
 486                                                 hops: vec![RouteHop {
 487                                                         pubkey: chan.remote_network_id,
 488                                                         short_channel_id,
 489                                                         fee_msat: final_value_msat,
 490                                                         cltv_expiry_delta: final_cltv,
 491                                                 }],
 492                                         });
 493                                 }
 494                                 first_hop_targets.insert(chan.remote_network_id, short_channel_id);
 495                         }
 496                         if first_hop_targets.is_empty() {
 497                                 return Err(HandleError{err: "Cannot route when there are no outbound routes away from us", action: None});
 498                         }
 499                 }
 500
 501                 macro_rules! add_entry {
 502                         // Adds entry which goes from the node pointed to by $directional_info to
 503                         // $dest_node_id over the channel with id $chan_id with fees described in
 504                         // $directional_info.
 505                         ( $chan_id: expr, $dest_node_id: expr, $directional_info: expr, $starting_fee_msat: expr ) => {
 506                                 //TODO: Explore simply adding fee to hit htlc_minimum_msat
 507                                 if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
 508                                         let proportional_fee_millions = ($starting_fee_msat + final_value_msat).checked_mul($directional_info.fee_proportional_millionths as u64);
 509                                         if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
 510                                                         ($directional_info.fee_base_msat as u64).checked_add(part / 1000000) })
 511                                         {
 512                                                 let mut total_fee = $starting_fee_msat as u64;
 513                                                 let hm_entry = dist.entry(&$directional_info.src_node_id);
 514                                                 let old_entry = hm_entry.or_insert_with(|| {
 515                                                         let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
 516                                                         (u64::max_value(),
 517                                                                 node.lowest_inbound_channel_fee_base_msat,
 518                                                                 node.lowest_inbound_channel_fee_proportional_millionths,
 519                                                                 RouteHop {
 520                                                                         pubkey: $dest_node_id.clone(),
 521                                                                         short_channel_id: 0,
 522                                                                         fee_msat: 0,
 523                                                                         cltv_expiry_delta: 0,
 524                                                         })
 525                                                 });
 526                                                 if $directional_info.src_node_id != network.our_node_id {
 527                                                         // Ignore new_fee for channel-from-us as we assume all channels-from-us
 528                                                         // will have the same effective-fee
 529                                                         total_fee += new_fee;
 530                                                         if let Some(fee_inc) = final_value_msat.checked_add(total_fee).and_then(|inc| { (old_entry.2 as u64).checked_mul(inc) }) {
 531                                                                 total_fee += fee_inc / 1000000 + (old_entry.1 as u64);
 532                                                         } else {
 533                                                                 // max_value means we'll always fail the old_entry.0 > total_fee check
 534                                                                 total_fee = u64::max_value();
 535                                                         }
 536                                                 }
 537                                                 let new_graph_node = RouteGraphNode {
 538                                                         pubkey: $directional_info.src_node_id,
 539                                                         lowest_fee_to_peer_through_node: total_fee,
 540                                                         lowest_fee_to_node: $starting_fee_msat as u64 + new_fee,
 541                                                 };
 542                                                 if old_entry.0 > total_fee {
 543                                                         targets.push(new_graph_node);
 544                                                         old_entry.0 = total_fee;
 545                                                         old_entry.3 = RouteHop {
 546                                                                 pubkey: $dest_node_id.clone(),
 547                                                                 short_channel_id: $chan_id.clone(),
 548                                                                 fee_msat: new_fee, // This field is ignored on the last-hop anyway
 549                                                                 cltv_expiry_delta: $directional_info.cltv_expiry_delta as u32,
 550                                                         }
 551                                                 }
 552                                         }
 553                                 }
 554                         };
 555                 }
 556
 557                 macro_rules! add_entries_to_cheapest_to_target_node {
 558                         ( $node: expr, $node_id: expr, $fee_to_target_msat: expr ) => {
 559                                 if first_hops.is_some() {
 560                                         if let Some(first_hop) = first_hop_targets.get(&$node_id) {
 561                                                 add_entry!(first_hop, $node_id, dummy_directional_info, $fee_to_target_msat);
 562                                         }
 563                                 }
 564
 565                                 for chan_id in $node.channels.iter() {
 566                                         let chan = network.channels.get(chan_id).unwrap();
 567                                         if chan.one_to_two.src_node_id == *$node_id {
 568                                                 // ie $node is one, ie next hop in A* is two, via the two_to_one channel
 569                                                 if first_hops.is_none() || chan.two_to_one.src_node_id != network.our_node_id {
 570                                                         if chan.two_to_one.enabled {
 571                                                                 add_entry!(chan_id, chan.one_to_two.src_node_id, chan.two_to_one, $fee_to_target_msat);
 572                                                         }
 573                                                 }
 574                                         } else {
 575                                                 if first_hops.is_none() || chan.one_to_two.src_node_id != network.our_node_id {
 576                                                         if chan.one_to_two.enabled {
 577                                                                 add_entry!(chan_id, chan.two_to_one.src_node_id, chan.one_to_two, $fee_to_target_msat);
 578                                                         }
 579                                                 }
 580                                         }
 581                                 }
 582                         };
 583                 }
 584
 585                 match network.nodes.get(target) {
 586                         None => {},
 587                         Some(node) => {
 588                                 add_entries_to_cheapest_to_target_node!(node, target, 0);
 589                         },
 590                 }
 591
 592                 for hop in last_hops.iter() {
 593                         if first_hops.is_none() || hop.src_node_id != network.our_node_id { // first_hop overrules last_hops
 594                                 if network.nodes.get(&hop.src_node_id).is_some() {
 595                                         if first_hops.is_some() {
 596                                                 if let Some(first_hop) = first_hop_targets.get(&hop.src_node_id) {
 597                                                         add_entry!(first_hop, hop.src_node_id, dummy_directional_info, 0);
 598                                                 }
 599                                         }
 600                                         add_entry!(hop.short_channel_id, target, hop, 0);
 601                                 }
 602                         }
 603                 }
 604
 605                 while let Some(RouteGraphNode { pubkey, lowest_fee_to_node, .. }) = targets.pop() {
 606                         if pubkey == network.our_node_id {
 607                                 let mut res = vec!(dist.remove(&network.our_node_id).unwrap().3);
 608                                 while res.last().unwrap().pubkey != *target {
 609                                         let new_entry = match dist.remove(&res.last().unwrap().pubkey) {
 610                                                 Some(hop) => hop.3,
 611                                                 None => return Err(HandleError{err: "Failed to find a non-fee-overflowing path to the given destination", action: None}),
 612                                         };
 613                                         res.last_mut().unwrap().fee_msat = new_entry.fee_msat;
 614                                         res.last_mut().unwrap().cltv_expiry_delta = new_entry.cltv_expiry_delta;
 615                                         res.push(new_entry);
 616                                 }
 617                                 res.last_mut().unwrap().fee_msat = final_value_msat;
 618                                 res.last_mut().unwrap().cltv_expiry_delta = final_cltv;
 619                                 let route = Route { hops: res };
 620                                 log_trace!(self, "Got route: {}", log_route!(route));
 621                                 return Ok(route);
 622                         }
 623
 624                         match network.nodes.get(&pubkey) {
 625                                 None => {},
 626                                 Some(node) => {
 627                                         add_entries_to_cheapest_to_target_node!(node, &pubkey, lowest_fee_to_node);
 628                                 },
 629                         }
 630                 }
 631
 632                 Err(HandleError{err: "Failed to find a path to the given destination", action: None})
 633         }
 634 }
 635
 636 #[cfg(test)]
 637 mod tests {
 638         use chain::chaininterface;
 639         use ln::channelmanager;
 640         use ln::router::{Router,NodeInfo,NetworkMap,ChannelInfo,DirectionalChannelInfo,RouteHint};
 641         use ln::msgs::GlobalFeatures;
 642         use util::test_utils;
 643         use util::logger::Logger;
 644
 645         use bitcoin::util::hash::Sha256dHash;
 646
 647         use hex;
 648
 649         use secp256k1::key::{PublicKey,SecretKey};
 650         use secp256k1::Secp256k1;
 651
 652         use std::sync::Arc;
 653
 654         #[test]
 655         fn route_test() {
 656                 let secp_ctx = Secp256k1::new();
 657                 let our_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap());
 658                 let logger: Arc<Logger> = Arc::new(test_utils::TestLogger::new());
 659                 let chain_monitor = Arc::new(chaininterface::ChainWatchInterfaceUtil::new(Network::Testnet, Arc::clone(&logger)));
 660                 let router = Router::new(our_id, chain_monitor, Arc::clone(&logger));
 661
 662                 // Build network from our_id to node8:
 663                 //
 664                 //        -1(1)2-  node1  -1(3)2-
 665                 //       /                       \
 666                 // our_id -1(12)2- node8 -1(13)2--- node3
 667                 //       \                       /
 668                 //        -1(2)2-  node2  -1(4)2-
 669                 //
 670                 //
 671                 // chan1  1-to-2: disabled
 672                 // chan1  2-to-1: enabled, 0 fee
 673                 //
 674                 // chan2  1-to-2: enabled, ignored fee
 675                 // chan2  2-to-1: enabled, 0 fee
 676                 //
 677                 // chan3  1-to-2: enabled, 0 fee
 678                 // chan3  2-to-1: enabled, 100 msat fee
 679                 //
 680                 // chan4  1-to-2: enabled, 100% fee
 681                 // chan4  2-to-1: enabled, 0 fee
 682                 //
 683                 // chan12 1-to-2: enabled, ignored fee
 684                 // chan12 2-to-1: enabled, 0 fee
 685                 //
 686                 // chan13 1-to-2: enabled, 200% fee
 687                 // chan13 2-to-1: enabled, 0 fee
 688                 //
 689                 //
 690                 //       -1(5)2- node4 -1(8)2--
 691                 //       |         2          |
 692                 //       |       (11)         |
 693                 //      /          1           \
 694                 // node3--1(6)2- node5 -1(9)2--- node7 (not in global route map)
 695                 //      \                      /
 696                 //       -1(7)2- node6 -1(10)2-
 697                 //
 698                 // chan5  1-to-2: enabled, 100 msat fee
 699                 // chan5  2-to-1: enabled, 0 fee
 700                 //
 701                 // chan6  1-to-2: enabled, 0 fee
 702                 // chan6  2-to-1: enabled, 0 fee
 703                 //
 704                 // chan7  1-to-2: enabled, 100% fee
 705                 // chan7  2-to-1: enabled, 0 fee
 706                 //
 707                 // chan8  1-to-2: enabled, variable fee (0 then 1000 msat)
 708                 // chan8  2-to-1: enabled, 0 fee
 709                 //
 710                 // chan9  1-to-2: enabled, 1001 msat fee
 711                 // chan9  2-to-1: enabled, 0 fee
 712                 //
 713                 // chan10 1-to-2: enabled, 0 fee
 714                 // chan10 2-to-1: enabled, 0 fee
 715                 //
 716                 // chan11 1-to-2: enabled, 0 fee
 717                 // chan11 2-to-1: enabled, 0 fee
 718
 719                 let node1 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()[..]).unwrap());
 720                 let node2 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()[..]).unwrap());
 721                 let node3 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()[..]).unwrap());
 722                 let node4 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()[..]).unwrap());
 723                 let node5 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0606060606060606060606060606060606060606060606060606060606060606").unwrap()[..]).unwrap());
 724                 let node6 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0707070707070707070707070707070707070707070707070707070707070707").unwrap()[..]).unwrap());
 725                 let node7 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0808080808080808080808080808080808080808080808080808080808080808").unwrap()[..]).unwrap());
 726                 let node8 = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &hex::decode("0909090909090909090909090909090909090909090909090909090909090909").unwrap()[..]).unwrap());
 727
 728                 let zero_hash = Sha256dHash::from_data(&[0; 32]);
 729
 730                 {
 731                         let mut network = router.network_map.write().unwrap();
 732
 733                         network.nodes.insert(node1.clone(), NodeInfo {
 734                                 channels: vec!(NetworkMap::get_key(1, zero_hash.clone()), NetworkMap::get_key(3, zero_hash.clone())),
 735                                 lowest_inbound_channel_fee_base_msat: 100,
 736                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 737                                 features: GlobalFeatures::new(),
 738                                 last_update: 1,
 739                                 rgb: [0; 3],
 740                                 alias: [0; 32],
 741                                 addresses: Vec::new(),
 742                         });
 743                         network.channels.insert(NetworkMap::get_key(1, zero_hash.clone()), ChannelInfo {
 744                                 features: GlobalFeatures::new(),
 745                                 one_to_two: DirectionalChannelInfo {
 746                                         src_node_id: our_id.clone(),
 747                                         last_update: 0,
 748                                         enabled: false,
 749                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 750                                         htlc_minimum_msat: 0,
 751                                         fee_base_msat: u32::max_value(), // This value should be ignored
 752                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 753                                 }, two_to_one: DirectionalChannelInfo {
 754                                         src_node_id: node1.clone(),
 755                                         last_update: 0,
 756                                         enabled: true,
 757                                         cltv_expiry_delta: 0,
 758                                         htlc_minimum_msat: 0,
 759                                         fee_base_msat: 0,
 760                                         fee_proportional_millionths: 0,
 761                                 },
 762                         });
 763                         network.nodes.insert(node2.clone(), NodeInfo {
 764                                 channels: vec!(NetworkMap::get_key(2, zero_hash.clone()), NetworkMap::get_key(4, zero_hash.clone())),
 765                                 lowest_inbound_channel_fee_base_msat: 0,
 766                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 767                                 features: GlobalFeatures::new(),
 768                                 last_update: 1,
 769                                 rgb: [0; 3],
 770                                 alias: [0; 32],
 771                                 addresses: Vec::new(),
 772                         });
 773                         network.channels.insert(NetworkMap::get_key(2, zero_hash.clone()), ChannelInfo {
 774                                 features: GlobalFeatures::new(),
 775                                 one_to_two: DirectionalChannelInfo {
 776                                         src_node_id: our_id.clone(),
 777                                         last_update: 0,
 778                                         enabled: true,
 779                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 780                                         htlc_minimum_msat: 0,
 781                                         fee_base_msat: u32::max_value(), // This value should be ignored
 782                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 783                                 }, two_to_one: DirectionalChannelInfo {
 784                                         src_node_id: node2.clone(),
 785                                         last_update: 0,
 786                                         enabled: true,
 787                                         cltv_expiry_delta: 0,
 788                                         htlc_minimum_msat: 0,
 789                                         fee_base_msat: 0,
 790                                         fee_proportional_millionths: 0,
 791                                 },
 792                         });
 793                         network.nodes.insert(node8.clone(), NodeInfo {
 794                                 channels: vec!(NetworkMap::get_key(12, zero_hash.clone()), NetworkMap::get_key(13, zero_hash.clone())),
 795                                 lowest_inbound_channel_fee_base_msat: 0,
 796                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 797                                 features: GlobalFeatures::new(),
 798                                 last_update: 1,
 799                                 rgb: [0; 3],
 800                                 alias: [0; 32],
 801                                 addresses: Vec::new(),
 802                         });
 803                         network.channels.insert(NetworkMap::get_key(12, zero_hash.clone()), ChannelInfo {
 804                                 features: GlobalFeatures::new(),
 805                                 one_to_two: DirectionalChannelInfo {
 806                                         src_node_id: our_id.clone(),
 807                                         last_update: 0,
 808                                         enabled: true,
 809                                         cltv_expiry_delta: u16::max_value(), // This value should be ignored
 810                                         htlc_minimum_msat: 0,
 811                                         fee_base_msat: u32::max_value(), // This value should be ignored
 812                                         fee_proportional_millionths: u32::max_value(), // This value should be ignored
 813                                 }, two_to_one: DirectionalChannelInfo {
 814                                         src_node_id: node8.clone(),
 815                                         last_update: 0,
 816                                         enabled: true,
 817                                         cltv_expiry_delta: 0,
 818                                         htlc_minimum_msat: 0,
 819                                         fee_base_msat: 0,
 820                                         fee_proportional_millionths: 0,
 821                                 },
 822                         });
 823                         network.nodes.insert(node3.clone(), NodeInfo {
 824                                 channels: vec!(
 825                                         NetworkMap::get_key(3, zero_hash.clone()),
 826                                         NetworkMap::get_key(4, zero_hash.clone()),
 827                                         NetworkMap::get_key(13, zero_hash.clone()),
 828                                         NetworkMap::get_key(5, zero_hash.clone()),
 829                                         NetworkMap::get_key(6, zero_hash.clone()),
 830                                         NetworkMap::get_key(7, zero_hash.clone())),
 831                                 lowest_inbound_channel_fee_base_msat: 0,
 832                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 833                                 features: GlobalFeatures::new(),
 834                                 last_update: 1,
 835                                 rgb: [0; 3],
 836                                 alias: [0; 32],
 837                                 addresses: Vec::new(),
 838                         });
 839                         network.channels.insert(NetworkMap::get_key(3, zero_hash.clone()), ChannelInfo {
 840                                 features: GlobalFeatures::new(),
 841                                 one_to_two: DirectionalChannelInfo {
 842                                         src_node_id: node1.clone(),
 843                                         last_update: 0,
 844                                         enabled: true,
 845                                         cltv_expiry_delta: (3 << 8) | 1,
 846                                         htlc_minimum_msat: 0,
 847                                         fee_base_msat: 0,
 848                                         fee_proportional_millionths: 0,
 849                                 }, two_to_one: DirectionalChannelInfo {
 850                                         src_node_id: node3.clone(),
 851                                         last_update: 0,
 852                                         enabled: true,
 853                                         cltv_expiry_delta: (3 << 8) | 2,
 854                                         htlc_minimum_msat: 0,
 855                                         fee_base_msat: 100,
 856                                         fee_proportional_millionths: 0,
 857                                 },
 858                         });
 859                         network.channels.insert(NetworkMap::get_key(4, zero_hash.clone()), ChannelInfo {
 860                                 features: GlobalFeatures::new(),
 861                                 one_to_two: DirectionalChannelInfo {
 862                                         src_node_id: node2.clone(),
 863                                         last_update: 0,
 864                                         enabled: true,
 865                                         cltv_expiry_delta: (4 << 8) | 1,
 866                                         htlc_minimum_msat: 0,
 867                                         fee_base_msat: 0,
 868                                         fee_proportional_millionths: 1000000,
 869                                 }, two_to_one: DirectionalChannelInfo {
 870                                         src_node_id: node3.clone(),
 871                                         last_update: 0,
 872                                         enabled: true,
 873                                         cltv_expiry_delta: (4 << 8) | 2,
 874                                         htlc_minimum_msat: 0,
 875                                         fee_base_msat: 0,
 876                                         fee_proportional_millionths: 0,
 877                                 },
 878                         });
 879                         network.channels.insert(NetworkMap::get_key(13, zero_hash.clone()), ChannelInfo {
 880                                 features: GlobalFeatures::new(),
 881                                 one_to_two: DirectionalChannelInfo {
 882                                         src_node_id: node8.clone(),
 883                                         last_update: 0,
 884                                         enabled: true,
 885                                         cltv_expiry_delta: (13 << 8) | 1,
 886                                         htlc_minimum_msat: 0,
 887                                         fee_base_msat: 0,
 888                                         fee_proportional_millionths: 2000000,
 889                                 }, two_to_one: DirectionalChannelInfo {
 890                                         src_node_id: node3.clone(),
 891                                         last_update: 0,
 892                                         enabled: true,
 893                                         cltv_expiry_delta: (13 << 8) | 2,
 894                                         htlc_minimum_msat: 0,
 895                                         fee_base_msat: 0,
 896                                         fee_proportional_millionths: 0,
 897                                 },
 898                         });
 899                         network.nodes.insert(node4.clone(), NodeInfo {
 900                                 channels: vec!(NetworkMap::get_key(5, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 901                                 lowest_inbound_channel_fee_base_msat: 0,
 902                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 903                                 features: GlobalFeatures::new(),
 904                                 last_update: 1,
 905                                 rgb: [0; 3],
 906                                 alias: [0; 32],
 907                                 addresses: Vec::new(),
 908                         });
 909                         network.channels.insert(NetworkMap::get_key(5, zero_hash.clone()), ChannelInfo {
 910                                 features: GlobalFeatures::new(),
 911                                 one_to_two: DirectionalChannelInfo {
 912                                         src_node_id: node3.clone(),
 913                                         last_update: 0,
 914                                         enabled: true,
 915                                         cltv_expiry_delta: (5 << 8) | 1,
 916                                         htlc_minimum_msat: 0,
 917                                         fee_base_msat: 100,
 918                                         fee_proportional_millionths: 0,
 919                                 }, two_to_one: DirectionalChannelInfo {
 920                                         src_node_id: node4.clone(),
 921                                         last_update: 0,
 922                                         enabled: true,
 923                                         cltv_expiry_delta: (5 << 8) | 2,
 924                                         htlc_minimum_msat: 0,
 925                                         fee_base_msat: 0,
 926                                         fee_proportional_millionths: 0,
 927                                 },
 928                         });
 929                         network.nodes.insert(node5.clone(), NodeInfo {
 930                                 channels: vec!(NetworkMap::get_key(6, zero_hash.clone()), NetworkMap::get_key(11, zero_hash.clone())),
 931                                 lowest_inbound_channel_fee_base_msat: 0,
 932                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 933                                 features: GlobalFeatures::new(),
 934                                 last_update: 1,
 935                                 rgb: [0; 3],
 936                                 alias: [0; 32],
 937                                 addresses: Vec::new(),
 938                         });
 939                         network.channels.insert(NetworkMap::get_key(6, zero_hash.clone()), ChannelInfo {
 940                                 features: GlobalFeatures::new(),
 941                                 one_to_two: DirectionalChannelInfo {
 942                                         src_node_id: node3.clone(),
 943                                         last_update: 0,
 944                                         enabled: true,
 945                                         cltv_expiry_delta: (6 << 8) | 1,
 946                                         htlc_minimum_msat: 0,
 947                                         fee_base_msat: 0,
 948                                         fee_proportional_millionths: 0,
 949                                 }, two_to_one: DirectionalChannelInfo {
 950                                         src_node_id: node5.clone(),
 951                                         last_update: 0,
 952                                         enabled: true,
 953                                         cltv_expiry_delta: (6 << 8) | 2,
 954                                         htlc_minimum_msat: 0,
 955                                         fee_base_msat: 0,
 956                                         fee_proportional_millionths: 0,
 957                                 },
 958                         });
 959                         network.channels.insert(NetworkMap::get_key(11, zero_hash.clone()), ChannelInfo {
 960                                 features: GlobalFeatures::new(),
 961                                 one_to_two: DirectionalChannelInfo {
 962                                         src_node_id: node5.clone(),
 963                                         last_update: 0,
 964                                         enabled: true,
 965                                         cltv_expiry_delta: (11 << 8) | 1,
 966                                         htlc_minimum_msat: 0,
 967                                         fee_base_msat: 0,
 968                                         fee_proportional_millionths: 0,
 969                                 }, two_to_one: DirectionalChannelInfo {
 970                                         src_node_id: node4.clone(),
 971                                         last_update: 0,
 972                                         enabled: true,
 973                                         cltv_expiry_delta: (11 << 8) | 2,
 974                                         htlc_minimum_msat: 0,
 975                                         fee_base_msat: 0,
 976                                         fee_proportional_millionths: 0,
 977                                 },
 978                         });
 979                         network.nodes.insert(node6.clone(), NodeInfo {
 980                                 channels: vec!(NetworkMap::get_key(7, zero_hash.clone())),
 981                                 lowest_inbound_channel_fee_base_msat: 0,
 982                                 lowest_inbound_channel_fee_proportional_millionths: 0,
 983                                 features: GlobalFeatures::new(),
 984                                 last_update: 1,
 985                                 rgb: [0; 3],
 986                                 alias: [0; 32],
 987                                 addresses: Vec::new(),
 988                         });
 989                         network.channels.insert(NetworkMap::get_key(7, zero_hash.clone()), ChannelInfo {
 990                                 features: GlobalFeatures::new(),
 991                                 one_to_two: DirectionalChannelInfo {
 992                                         src_node_id: node3.clone(),
 993                                         last_update: 0,
 994                                         enabled: true,
 995                                         cltv_expiry_delta: (7 << 8) | 1,
 996                                         htlc_minimum_msat: 0,
 997                                         fee_base_msat: 0,
 998                                         fee_proportional_millionths: 1000000,
 999                                 }, two_to_one: DirectionalChannelInfo {
1000                                         src_node_id: node6.clone(),
1001                                         last_update: 0,
1002                                         enabled: true,
1003                                         cltv_expiry_delta: (7 << 8) | 2,
1004                                         htlc_minimum_msat: 0,
1005                                         fee_base_msat: 0,
1006                                         fee_proportional_millionths: 0,
1007                                 },
1008                         });
1009                 }
1010
1011                 { // Simple route to 3 via 2
1012                         let route = router.get_route(&node3, None, &Vec::new(), 100, 42).unwrap();
1013                         assert_eq!(route.hops.len(), 2);
1014
1015                         assert_eq!(route.hops[0].pubkey, node2);
1016                         assert_eq!(route.hops[0].short_channel_id, 2);
1017                         assert_eq!(route.hops[0].fee_msat, 100);
1018                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1019
1020                         assert_eq!(route.hops[1].pubkey, node3);
1021                         assert_eq!(route.hops[1].short_channel_id, 4);
1022                         assert_eq!(route.hops[1].fee_msat, 100);
1023                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1024                 }
1025
1026                 { // Route to 1 via 2 and 3 because our channel to 1 is disabled
1027                         let route = router.get_route(&node1, None, &Vec::new(), 100, 42).unwrap();
1028                         assert_eq!(route.hops.len(), 3);
1029
1030                         assert_eq!(route.hops[0].pubkey, node2);
1031                         assert_eq!(route.hops[0].short_channel_id, 2);
1032                         assert_eq!(route.hops[0].fee_msat, 200);
1033                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1034
1035                         assert_eq!(route.hops[1].pubkey, node3);
1036                         assert_eq!(route.hops[1].short_channel_id, 4);
1037                         assert_eq!(route.hops[1].fee_msat, 100);
1038                         assert_eq!(route.hops[1].cltv_expiry_delta, (3 << 8) | 2);
1039
1040                         assert_eq!(route.hops[2].pubkey, node1);
1041                         assert_eq!(route.hops[2].short_channel_id, 3);
1042                         assert_eq!(route.hops[2].fee_msat, 100);
1043                         assert_eq!(route.hops[2].cltv_expiry_delta, 42);
1044                 }
1045
1046                 { // If we specify a channel to node8, that overrides our local channel view and that gets used
1047                         let our_chans = vec![channelmanager::ChannelDetails {
1048                                 channel_id: [0; 32],
1049                                 short_channel_id: Some(42),
1050                                 remote_network_id: node8.clone(),
1051                                 channel_value_satoshis: 0,
1052                                 user_id: 0,
1053                         }];
1054                         let route = router.get_route(&node3, Some(&our_chans), &Vec::new(), 100, 42).unwrap();
1055                         assert_eq!(route.hops.len(), 2);
1056
1057                         assert_eq!(route.hops[0].pubkey, node8);
1058                         assert_eq!(route.hops[0].short_channel_id, 42);
1059                         assert_eq!(route.hops[0].fee_msat, 200);
1060                         assert_eq!(route.hops[0].cltv_expiry_delta, (13 << 8) | 1);
1061
1062                         assert_eq!(route.hops[1].pubkey, node3);
1063                         assert_eq!(route.hops[1].short_channel_id, 13);
1064                         assert_eq!(route.hops[1].fee_msat, 100);
1065                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1066                 }
1067
1068                 let mut last_hops = vec!(RouteHint {
1069                                 src_node_id: node4.clone(),
1070                                 short_channel_id: 8,
1071                                 fee_base_msat: 0,
1072                                 fee_proportional_millionths: 0,
1073                                 cltv_expiry_delta: (8 << 8) | 1,
1074                                 htlc_minimum_msat: 0,
1075                         }, RouteHint {
1076                                 src_node_id: node5.clone(),
1077                                 short_channel_id: 9,
1078                                 fee_base_msat: 1001,
1079                                 fee_proportional_millionths: 0,
1080                                 cltv_expiry_delta: (9 << 8) | 1,
1081                                 htlc_minimum_msat: 0,
1082                         }, RouteHint {
1083                                 src_node_id: node6.clone(),
1084                                 short_channel_id: 10,
1085                                 fee_base_msat: 0,
1086                                 fee_proportional_millionths: 0,
1087                                 cltv_expiry_delta: (10 << 8) | 1,
1088                                 htlc_minimum_msat: 0,
1089                         });
1090
1091                 { // Simple test across 2, 3, 5, and 4 via a last_hop channel
1092                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1093                         assert_eq!(route.hops.len(), 5);
1094
1095                         assert_eq!(route.hops[0].pubkey, node2);
1096                         assert_eq!(route.hops[0].short_channel_id, 2);
1097                         assert_eq!(route.hops[0].fee_msat, 100);
1098                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1099
1100                         assert_eq!(route.hops[1].pubkey, node3);
1101                         assert_eq!(route.hops[1].short_channel_id, 4);
1102                         assert_eq!(route.hops[1].fee_msat, 0);
1103                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1104
1105                         assert_eq!(route.hops[2].pubkey, node5);
1106                         assert_eq!(route.hops[2].short_channel_id, 6);
1107                         assert_eq!(route.hops[2].fee_msat, 0);
1108                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1109
1110                         assert_eq!(route.hops[3].pubkey, node4);
1111                         assert_eq!(route.hops[3].short_channel_id, 11);
1112                         assert_eq!(route.hops[3].fee_msat, 0);
1113                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1114
1115                         assert_eq!(route.hops[4].pubkey, node7);
1116                         assert_eq!(route.hops[4].short_channel_id, 8);
1117                         assert_eq!(route.hops[4].fee_msat, 100);
1118                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1119                 }
1120
1121                 { // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
1122                         let our_chans = vec![channelmanager::ChannelDetails {
1123                                 channel_id: [0; 32],
1124                                 short_channel_id: Some(42),
1125                                 remote_network_id: node4.clone(),
1126                                 channel_value_satoshis: 0,
1127                                 user_id: 0,
1128                         }];
1129                         let route = router.get_route(&node7, Some(&our_chans), &last_hops, 100, 42).unwrap();
1130                         assert_eq!(route.hops.len(), 2);
1131
1132                         assert_eq!(route.hops[0].pubkey, node4);
1133                         assert_eq!(route.hops[0].short_channel_id, 42);
1134                         assert_eq!(route.hops[0].fee_msat, 0);
1135                         assert_eq!(route.hops[0].cltv_expiry_delta, (8 << 8) | 1);
1136
1137                         assert_eq!(route.hops[1].pubkey, node7);
1138                         assert_eq!(route.hops[1].short_channel_id, 8);
1139                         assert_eq!(route.hops[1].fee_msat, 100);
1140                         assert_eq!(route.hops[1].cltv_expiry_delta, 42);
1141                 }
1142
1143                 last_hops[0].fee_base_msat = 1000;
1144
1145                 { // Revert to via 6 as the fee on 8 goes up
1146                         let route = router.get_route(&node7, None, &last_hops, 100, 42).unwrap();
1147                         assert_eq!(route.hops.len(), 4);
1148
1149                         assert_eq!(route.hops[0].pubkey, node2);
1150                         assert_eq!(route.hops[0].short_channel_id, 2);
1151                         assert_eq!(route.hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
1152                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1153
1154                         assert_eq!(route.hops[1].pubkey, node3);
1155                         assert_eq!(route.hops[1].short_channel_id, 4);
1156                         assert_eq!(route.hops[1].fee_msat, 100);
1157                         assert_eq!(route.hops[1].cltv_expiry_delta, (7 << 8) | 1);
1158
1159                         assert_eq!(route.hops[2].pubkey, node6);
1160                         assert_eq!(route.hops[2].short_channel_id, 7);
1161                         assert_eq!(route.hops[2].fee_msat, 0);
1162                         assert_eq!(route.hops[2].cltv_expiry_delta, (10 << 8) | 1);
1163
1164                         assert_eq!(route.hops[3].pubkey, node7);
1165                         assert_eq!(route.hops[3].short_channel_id, 10);
1166                         assert_eq!(route.hops[3].fee_msat, 100);
1167                         assert_eq!(route.hops[3].cltv_expiry_delta, 42);
1168                 }
1169
1170                 { // ...but still use 8 for larger payments as 6 has a variable feerate
1171                         let route = router.get_route(&node7, None, &last_hops, 2000, 42).unwrap();
1172                         assert_eq!(route.hops.len(), 5);
1173
1174                         assert_eq!(route.hops[0].pubkey, node2);
1175                         assert_eq!(route.hops[0].short_channel_id, 2);
1176                         assert_eq!(route.hops[0].fee_msat, 3000);
1177                         assert_eq!(route.hops[0].cltv_expiry_delta, (4 << 8) | 1);
1178
1179                         assert_eq!(route.hops[1].pubkey, node3);
1180                         assert_eq!(route.hops[1].short_channel_id, 4);
1181                         assert_eq!(route.hops[1].fee_msat, 0);
1182                         assert_eq!(route.hops[1].cltv_expiry_delta, (6 << 8) | 1);
1183
1184                         assert_eq!(route.hops[2].pubkey, node5);
1185                         assert_eq!(route.hops[2].short_channel_id, 6);
1186                         assert_eq!(route.hops[2].fee_msat, 0);
1187                         assert_eq!(route.hops[2].cltv_expiry_delta, (11 << 8) | 1);
1188
1189                         assert_eq!(route.hops[3].pubkey, node4);
1190                         assert_eq!(route.hops[3].short_channel_id, 11);
1191                         assert_eq!(route.hops[3].fee_msat, 1000);
1192                         assert_eq!(route.hops[3].cltv_expiry_delta, (8 << 8) | 1);
1193
1194                         assert_eq!(route.hops[4].pubkey, node7);
1195                         assert_eq!(route.hops[4].short_channel_id, 8);
1196                         assert_eq!(route.hops[4].fee_msat, 2000);
1197                         assert_eq!(route.hops[4].cltv_expiry_delta, 42);
1198                 }
1199         }
1200 }